import  sys
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
class ScollDemo(QWidget):

    def __init__(self):
        super(ScollDemo,self).__init__()
        self.initUI()
    def initUI(self):
        hbox=QHBoxLayout()
        self.l1=QLabel("拖动滑块改变颜色")
        self.l1.setFont(QFont("Arial",20))
        hbox.addWidget(self.l1)
        self.s1=QScrollBar()
        self.s1.setMaximum(255)
        self.s1.sliderMoved.connect(self.sliderval)

        self.s2 = QScrollBar()
        self.s2.setMaximum(255)
        self.s2.sliderMoved.connect(self.sliderval)
        self.s3 = QScrollBar()
        self.s3.setMaximum(255)
        self.s3.sliderMoved.connect(self.sliderval)

        hbox.addWidget(self.s1)
        hbox.addWidget(self.s2)
        hbox.addWidget(self.s3)
        self.setGeometry(300,300,300,250)
        self.setWindowTitle("Sco案例")
        self.setLayout(hbox)
    def sliderval(self):
        pl=QPalette()
        c=QColor(self.s1.value(),self.s2.value(),self.s3.value(),255)
        pl.setColor(QPalette.Foreground,c)
        self.l1.setPalette(pl)
if __name__ == '__main__':
    app=QApplication(sys.argv)
    demo=ScollDemo()

    demo.show()
    sys.exit(app.exec_())
